Drill core extractor

ABSTRACT

A system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill core samples without the time-consuming fishing method therefore increasing productivity by a substantial margin.

FIELD OF THE INVENTION

The present invention relates to a system for extracting drill coresfrom a borehole. The system enables a semi-resilient sleeve-inserted ina housing—to be sealed about the circumference of a drill rod therebyallowing for upward backpressure against the drill core when activated.The system comprises: a housing assembly having sleeve retaining annularrings with edge treatment that forces outward displacement of thecentral region of the sleeve so as to ensure utmost clearance from adrill rod, which traverses said sleeve. The system thereby allowsextraction of drill cores without the time-consuming fishing methodtherefore increasing productivity by a substantial margin.

BACKGROUND OF THE INVENTION

One of the many facets of hard rock mining is exploration drillingcomprising generally of boring core samples in bed rock to obtain aclearer picture within the ore body. This in presently accomplished byboring through an ore body using a hollow drill bit and drill rods;leaving a central core within an annular cut in the ore body. Cores areleft is the center of a core tube within the hollow drill rod forintermittent extraction. Presently, the core tube retrieval process ismuch like fishing; involving a long wire cable having latching means toa mating receiving portion at the upper end of the core tube. Oncelatched, the cable is then pulled upward along with the core tube, whichcontains the core sample. The process is repeated intermittently untilthe desired core depth is achieved. This retrieval process accounts fornearly 50% of the available drilling time.

The inventor sought to provide miners with a device and system thatgreatly reduces core retrieval time so as to increase actual drillingtime per work shift.

The applicant failed in finding attempts in prior art that providesimilar methodologies for core extraction.

While attempts have been made to refine core-extraction systems, noprior art provides sleeve sealing of drill rods as a means to use waterbackpressure to extract core samples at a much speedier rate.

SUMMARY OF THE INVENTION

It is thus the object of the present invention to provide the hard rockmining industry with a core extraction system-using sleeve sealing ofdrill rods as a means to utilize water backpressure to extract coresamples.

In one aspect of the invention, the sleeve may comprise any suitablesemi-resilient material type, which has low friction quality.

In another aspect of the invention, inner diameter of the sleeve isdirectly proportional to the outer diameter of the traversing rod.

Accordingly, the device of the present invention therefore provides thehard rock mining industry with a core extraction system-using sleevesealing of drill rods as a means to utilize water backpressure toextract core samples.

The utility of the present invention includes but is not limited to rockdrill-cores.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the invention will become apparent uponreading the following brief description and upon referring to thedrawings in which:—

FIG. 1 is a perspective exploded view of the seal assembly of thepresent invention.

FIG. 2 is a partially cross-sectioned view of the seal assembly of thepresent invention.

FIG. 3 is a cross-sectioned view of the seal assembly of the presentinvention shown with the rod seal in a rested position.

FIG. 4 is a cross-sectioned view of the seal assembly of the presentinvention shown with the rod seal in a compressed position.

FIG. 5 is a cross-sectional view selected from FIG. 3 of the sealassembly of the present invention shown prior to full tightening of theassembly.

FIG. 6 is a cross-sectional view selected from FIG. 3 of the sealassembly of the present invention shown after full tightening of theassembly.

FIG. 7 is a cross-sectioned elevation view of the seal assembly of thepresent invention shown installed ready for drilling.

FIG. 8 is a cross-sectioned elevation view of the seal assembly of thepresent invention shown installed ready for core extraction.

While the invention is described in conjunction with preferredillustrated embodiments, it will be understood that it is not intendedto limit the invention to such embodiments. On the contrary, it isintended to cover all alternatives, modifications and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following description, similar features in the drawings have beengiven similar reference numerals.

Although exploration drilling is generally oriented to a downward andupward vertical axis, mild angles are at times used. However, forclarity and illustration of the present invention, the specificationwill depict the common downward vertical orientation.

Turning now to FIG. 1, a perspective exploded view of the seal assembly2 of the present invention generally comprising; a male casing adapter10, a grip ring 20, a sleeve housing 30, a retainer ring 40, an upperoil seal 45, a lower oil seal 48, a sleeve 50, a form ring 52, a waterinlet 60, a water outlet 70, and an oil inlet.

Turning to FIG. 2, a partially cross-sectioned view of the seal assemblyof the present invention further comprising:—a male casing adapter 10having a rigid tubular body threaded at a lower end to mate with afemale casing adapter, and a forming end 12, water ports 14, and anattachment flange 16 about the full circumference of the tubular adapter10 wherein said flange further comprises a plurality of fastenerperforations therethrough,—a semi-resilient grip ring 20 having aplurality of fastener perforations therethrough and in direct alignmentwith those of the male casing adapter 10, and a plurality of grip slots21 arrayed about the grip ring's 20 outer circumference for use to applya wrench therein for rotable insertion and removal of the assembly 2 onand off a female casing adapter,—a sleeve housing 30 having a roundtubular body with a lower flange 22 having a plurality of fastenerperforations therethrough in direct alignment with those of the malecasing adapter 10 and the grip ring 20, and an upper flange 23 alsohaving a plurality of fastener perforations therethrough in directalignment with those of a retainer ring 40, a water inlet 60 angularlyand threadedly engaged above the base of the sleeve housing 30 and indirect alignment with a first water port 14 within the male casingadapter 10, a water outlet 70 also angularly and threadedly engagedabove the base of the sleeve housing 30 distal from the inlet 60 andalso in direct alignment with a second water port 14 within the malecasing adapter 10, an outwardly raised continuous annular depression 81located centrally within the sleeve housing 30 through which an oilinlet 81 is adapted,—a retainer ring 40 comprising a annular flangedbody with a raised central diameter adapted to engage frictionallywithin an opening of the upper portion of the sleeve housing 30 and saidflanged body also having a plurality of fastener perforationstherethrough in direct alignment with those of the upper flange 23 ofthe sleeve housing 30,—an upper oil seal 45 frictionally retained withina seal slot at the upper inner portion of the sleeve housing 30, whichsaid upper oil seal 45 also engages frictionally against the outercircumference of the raised central portion of the retainer ring 40 thusforming a positive seal therebetween,—a lower oil seal 48 alsofrictionally retained within a seal slot at the lower inner portion ofthe sleeve housing 30, which said upper oil seal 48 also engagesfrictionally against the outer circumference of the male casing adapter10 also forming a positive seal therebetween,—a sleeve 50 fabricated ofa semi-resilient rubber-like compound, which said sleeve 50 having anouter diameter generally equal to that of the inner diameter of thesleeve housing 30 and a length slightly greater than the distancebetween a form ring 52 and the forming end 12 at the uppermost portionof the male casing adapter,—a form ring 52 having an annular bodywherein its upper face is planar and its inner face is adapted with twocircumferential peaks,—an oil inlet 80 threadedly engaged through thesleeve housing 30 wherein the oil inlet 80 is in communication with theoutwardly raised continuous annular depression 81 located centrallywithin said sleeve housing 30, and fasteners 85 securedly holding theassembly as one.

Turning to FIG. 3, a cross-sectioned view of the seal assembly 2 of thepresent invention shown with the sleeve 50 in a rested position whereina drill rod 35 traverses the assembly 2 and said rod 35 is free torotate within the assembly 2. This configuration is thus used during thedrilling process where water is pumped at a lower rate through and downthe drill rod, out the drill bit, up the drill rod then ejected out thewater outlet 70 to provide cooling of the drill bit down the bore.Conversely, the water inlet 60 may be adapted to alternate in usebetween inlet and outlet.

Turning now to FIG. 4, a similar cross-sectioned view of the sealassembly 2 of the present invention shown with the sleeve 50 in acompressed position wherein—rotation of the drill rod is halted andhydraulic oil is compressed at a high rate via the oil inlet. The oilthen pressurizes the space between the inner surface of the sleevehousing 30 and the sleeve 50. The sleeve's 50 end seal is maintained bybeing compressed between the form ring 52 above said sleeve 50 and theforming end 12 at the uppermost portion of the male casing adapter 10thereby creating an annular pinch valve about the circumference of thedrill rod.

Referring now to FIG. 5, depicting a better cross-sectional viewselected from FIG. 3 of the seal assembly of the present invention shownprior to full tightening of the fasteners of the assembly wherein anupper oil seal 45 frictionally retained within a seal slot at the upperinner portion of the sleeve housing 30, which said upper oil seal 45also engages frictionally against the outer circumference of the raisedcentral portion of the retainer ring 40 thus forming a positive sealtherebetween. A closer look at the contacting area adjacent each end ofthe sleeve 50 is also depicted wherein a form ring 52 having an annularbody wherein its upper face is planar and its inner face is adapted withtwo circumferential peaks 55 & 56. The innermost peak 55 extendingtoward the sleeve more so than the outer peak 56, which said peak 56 israther slightly recessed. This arrangement is simply mirrored at thesleeve's 50 opposing end with the exception that the peak formation atthe opposing end is integral with the uppermost edge of the male casingadapter. Conversely, the upper form ring 52 may be integral to theretainer ring 40.

FIG. 6, also a cross-sectional view selected from FIG. 3 of the sealassembly of the present invention shown after full tightening of theassembly wherein once the assembly is fully assembled and tightened, thesleeve 50 becomes compressed while the offset peaks 55 & 56 encourage anoutward central bulge tendency at the sleeve's circumference therebyensuring maximum clearance between the sleeve's inner surface and thedrill rod's outer surface as best illustrated in FIG. 3.

Turning now to FIG. 7, a cross-sectioned elevation view of the sealassembly of the present invention as shown installed and ready fordrilling wherein the configuration entails: an ore body 90 in which apit 91 is bored so as to insert a female casing 92 set in place withinthe pit 91 using grout 93 so as to seal and immobilize the casing 92with the ore body 90. The seal assembly 2 is threadedly engaged with thefemale casing 92, and a drilling rig attached to the drill rod 35 as percurrent practice.

In the drilling process, the sleeve 50 is depressurized, allowing it toretract away from the drill rod 35 with sufficient clearance so as toprevent friction against the rotating drill rod 35. Water is pumped downthrough the center of the drill rod 35 where it reaches the drill bit 36to cool said bit 36. The water then exits the bit end through aplurality of slots at the bit's lower periphery where said water findsits way up the drilled bore wall where it is forcedly directed to one ormore water outlets 60 & 70.

Let's turn to FIG. 8, a cross-sectioned elevation view of the sealassembly of the present invention shown installed ready for coreextraction wherein the configuration similarly entails: an ore body 90in which a pit 91 is bored so as to insert a female casing 92 set inplace within the pit 91 using grout 93 so as to seal and immobilize thecasing 92 with the ore body 90. The seal assembly 2 is threadedlyengaged with the female casing 92, and a drilling rig attached to thedrill rod 35.

In the core extraction process, rotation of the drill rod 35 is haltedand only the drill head is removed. Hydraulic oil is compressed at ahigh rate via the oil inlet 80; pressurizing the space between the innersurface of the sleeve housing 30 and the sleeve 50 creating an annularpinch valve about the circumference of the drill rod 35. Water is nowpumped into the water inlet 60 down along the drill rod 35 outer wallwithin the bore where it reaches the drill bit 36. The pressurized waterthen enters the bit end through a plurality of slots at the bit's lowerperiphery where said water finds its way up the drill rod's 35 centerapplying upward force against the base of the core sample 100 therebyextracting the core 100 longitudinally up the drill rod 35. Oncesurfaced, the core sample is collected. Water pressure is then removedat the drill head re-installed onto the drill core for yet anotherdrilling cycle.

Upon referring to the drawing figures and the above specification, itcan now be understood how pinch-sealing the immobilized drill rod canafford miners the ability to reverse the water flow to use existingsystems along with the present invention to speed the core retrievalprocess.

1. A drill core extractor comprising: a. a seal assembly having: i. amale casing adapter comprising: a rigid tubular body threaded at a lowerend to mate with a female casing, a forming end, water ports, anattachment flange about the full circumference of the tubular adapterwherein said flange further comprises a plurality of fastenerperforations therethrough, ii.—a grip ring having a plurality offastener perforations therethrough and in direct alignment with those ofthe male casing adapter, and a plurality of grip slots arrayed about thegrip ring's outer circumference for use to apply a wrench therein forrotable insertion and removal of the assembly on and off a female casingadapter, iii.—a sleeve housing having a round tubular body with a lowerflange having a plurality of fastener perforations therethrough indirect alignment with those of the male casing adapter and the gripring, and an upper flange also having a plurality of fastenerperforations therethrough in direct alignment with those of a retainerring, a water inlet angularly and threadedly engaged above the base ofthe sleeve housing and in direct alignment with a first water portwithin the male casing adapter, a water outlet also angularly andthreadedly engaged above the base of the sleeve housing distal from theinlet and also in direct alignment with a second water port within themale casing adapter, an outwardly raised continuous annular depressionlocated centrally within the sleeve housing inner wall through which anoil inlet is adapted, iv.—a retainer ring comprising a annular flangedbody with a raised central diameter adapted to engage frictionallywithin an opening of the upper portion of the sleeve housing and saidflanged body also having a plurality of fastener perforationstherethrough in direct alignment with those of the upper flange of thesleeve housing, v.—an upper oil seal frictionally retained within a sealslot at the upper inner portion of the sleeve housing, which said upperoil seal also engages frictionally against the outer circumference ofthe raised central portion of the retainer ring thus forming animpermeable seal therebetween, vi.—a lower oil seal also frictionallyretained within a seal slot at the lower inner portion of the sleevehousing, which said upper oil seal also engages frictionally against theouter circumference of the male casing adapter also forming animpermeable seal therebetween, vii.—a sleeve fabricated of asemi-resilient rubber-like compound, which said sleeve having an outerdiameter generally equal to that of the inner diameter of the sleevehousing and a length slightly greater than the distance between a formring and the forming end at the uppermost portion of the male casingadapter, viii.—a form ring having an annular body wherein its upper faceis planar and its inner face is adapted with two circumferential peaks,ix.—an oil inlet threadedly engaged through the sleeve housing whereinthe oil inlet is in communication with the outwardly raised continuousannular depression located centrally within said sleeve housing, andfasteners securedly holding the assembly as one. b. a method ofextracting drill core samples comprising the steps of: i. de-energizingthe drill to halt rotation, ii. removing drill head from drill rod, iii.pressurizing hydraulic sleeve seal about the periphery of the drill rod,iv. activating water pump and directing high-pressure water into thewater inlet, V. allow core sample to attain a height sufficient enoughto surface above drill rod, vi. grasp core sample for retrieval fromdrill rod, vii. re-assemble drill head, reconfigure water flows,de-pressurize sleeve seal and continue drilling.
 2. The drill coreextractor of claim 1 wherein the present seal assembly can be adaptedwith current water cooling hard rock drilling rig systems without theaddition of specialized tools.
 3. The drill core extractor of claim 1wherein the direction of water-flow through the drill rod is reversedduring the core extraction process.
 4. The drill core extractor of claim1 wherein the male casing adapter is further adapted with a forming endhaving two circumferential offset peaks oriented such that the peakspressuredly contact with the circumferencial end surface of a tubularsleeve, wherein the central-most peak extends toward the sleeve more sothan the outer peak, which said outer peak is rather slightly recessedthereby encouraging an outward central bulge tendency at the sleeve'scircumference.
 5. The drill core extractor of claim 1 wherein theretainer ring is further adapted with a forming end having twocircumferential offset peaks oriented such that the peaks pressuredlycontact with the circumferencial end surface of a tubular sleeve,wherein the central-most peak extends toward the sleeve more so than theouter peak, which said outer peak is rather slightly recessed therebyencouraging an outward central bulge tendency at the sleeve'scircumference.
 6. The drill core extractor of claim 5 wherein theforming end of the retainer ring is oriented in mirror image of theforming end of the male casing adapter.
 7. The drill core extractor ofclaim 1 wherein the outwardly raised continuous annular depressionlocated centrally within the sleeve housing inner wall enables a bodycircumferential communication of compressed fluid to exert equal foragainst the sleeve's outer wall so as to ensure the sleeve's inner wallmates evenly about the outer diameter of an immobilized drill rod.